To find the measure of angle \( a \), we start with the equation for complementary angles:
\[ a + b = 90^\circ \]
Given that the measure of angle \( b \) is \( 38^\circ \), we can substitute this value into the equation:
\[ a + 38 = 90 \]
Now, to isolate \( a \), we subtract \( 38 \) from both sides:
\[ a = 90 - 38 \] \[ a = 52^\circ \]
Now that we have the measure of angle \( a \) (which is \( 52^\circ \)), we can find the measure of angle \( f \) using the equation for supplementary angles:
\[ a + f = 180^\circ \]
Substituting the value of \( a \):
\[ 52 + f = 180 \]
To isolate \( f \), we subtract \( 52 \) from both sides:
\[ f = 180 - 52 \] \[ f = 128^\circ \]
Thus, the measure of angle \( f \) is \( 128^\circ \).